No way to specify assembly flags at configure time

It's possible to use configure flags like CONF_CC_OPTS_STAGE2 to specify C compile-time flag, which will be recorded into the settings file and used later, but there's no way to specify assembly flags (or more exotic languages like objc).

To avoid the XY problem a bit: I need to pass -Wa,-no-type-check to all wasm32 assembly sources. I can hard-code this logic in runAsPhase, but the lack of ability to specify assembly flags at configure time doesn't feel quite right.